Telephone signal-circuit.



No. 644,868. Patented Mar. 6, I900.

n. mum.

TELEPHONE SIGNAL CIRCUIT.

(Application filed July 12, 1899.)

(Ho Modal.)

lD'ANA McNEIL, OF CHADRON, NEBRASKA.

TELEPHONE s|cNAL-o|Rou|T.

s'rncrrrcA'r'roiv forming part of Letters Patent No. 644,868, dated March a, 1900.

Application filed nly 12, 1 899. Serial No. 723,5 24-.- (No model.)

T0 at whom it may concern:

Be it known that I, DANA MONEIL, a citizen of the United States, residing at Chadron, county of Dawes, and State of Nebraska, have invented certain new and useful Improvements in Telephone Signal-Circuits; and I do hereby declare the following to be a full, clear, and exact description, such as will enable persons skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in telephone signal-circuits, wherein I provide a new system of circuits. The arrangement and locations of the elements constituting a system of this nature form an important and essential feature of my invention.

One object of my invention is to provide a system whereby all of-the signal-bells included in a circuit may be clearly sounded from any distant station in line-circuits where more cuits being commonly known as manyparty circuits or lines.

A further object of my invention is to remove the signal-bells from the talking-circuits; and a still further improvement consists in a means whereby a minimum portion of energy of the magneto-generator is employed for operating the home bell, the major portion of the energy thereof being reserved to overcome the intervening resistance and for operating the distant bells in the system.

lVith these and other objects in view my invention consists in the novel constructions and combinations of parts and the organiza tion of the elements employed in a system hereinafter more fully described, and particularly pointed out in the appended claims.

In the drawings, Figure l is a diagrammatic View of circuit-wires having three stations connected thereto. Fig. 2 is a detail of a conventional switch associated with the genera- In like manner the terminals of stations B and ing the bells.

C are represented by B B and C 0', respec tively.

The main-line wires that connect the sev= eral stations are represented by the numerals 1 and 2.

In describing the various parts in station A it Will be seen that the same parts are re-,

the crank preliminary to ringing the bells.

A cha'racteristically-conventional switch, familiar to persons skilled in the art, is shown in detail in Fig. 2. loosely mounted upon the armature-shaft o and is driven by the pin a through the slot a A spiral spring a presses the disk outwardly toward the handle, so that normally the disk makes contact with contact brushes or springs a and o As shown in 2, the positions are such as the various parts will assume while the handle is being turned for the purpose of developing current for ring- In this case the disk has made contact with brush 01. and the current from the magneto will traverse the circuit thus established, while contacts a and a are broken or at these points the circuits are open. a", a and ct are stop-pins against which the respective brushes rest when the disk a is moved away from'them. The effect of turning the crank displaces the disk a laterally toward and-against the spring a and spring wound upon the same magnets.

The terminal of the high-resistance coils a A metallic disk 0. is-

and 0. is connected to brush a by wire 3, and the like terminal of the low-resistance coils a and a" is connected to brush a by wire 4. The remaining terminals of the two sets of coils are connected to A (station-terminals) by wire 5, to which line-wire No. 2 also is attached.

I have shown the conventional receiver, transmitter, and automatic hook, and for the sake of clearness I have left out the primary circuit of the transmitter, as that is not essential to the operation of my new system.

The magneto-generator a is connected to the lower contact of the automatic hook by wire 6*. Wire '7 short-circuits the generator a when the disk a makes contact with brush a. The automatic hook is connected to A by wire 8, to which line-Wire No. 1 is also connected. Wire 9 connects terminals A with one terminal of the receiver. The remaining terminal at the receiver is connected to one of the upper terminals to which the hook makes contact by wire 10*.

Previous to my invention the coils of signal-bells have been connected in telephonecircuits either in series or multiple, the latter method being known in telephone vernacular as bridging the bells -that is, connecting them in parallel circuit with the two main wires. When the bells are bridged in the manner described, it is necessary that it should be wound to a high resistance, so that they may possess a large coefficient of selfinduction, by which they impede the highly vibratory voice-currents, but permit the more slowly vibrating magneto signal-currents to pass through them and by that effect operate the bells. In systems where bells are bridged in circuit the current from the magneto will divide, and an approximately-equal portion will pass through each pair of hellmagnets. For this purpose the magneto should be Wound for sufficient electromotive' force for the most distant bell, including the interveningline-circuit. Theinternalresistance (the carrying capacity of the armaturewindings of the magneto) should be proportional to the number of bells to be rung at one time or to the current required to be delivered. In other bridging bell systems the home bell of the calling station is the one that usually rings the loudest, for the reason that possessing the same resistance and impedance and being in parallel with other bells of'its kind that are removed by intervening line-resistance of some considerable proportion a greater current will be directed through the home bell of the calling station than will flow through the distant bells in series with the said intervening line-wires. It follows from the nature of the uses for which a system of this character is designed that the relative resistance or winding of the various signal-bell magnets cannot be predetermined. A calling station at one time may become a called station a few moments later, and therefore it is expedient to wind allot the call-bellmagnet coils exactly alike.

At the calling or home station it is not necessary that the bell should be rung with much vigor. A very feeble tap or two to indicate to the user that the circuit is complete is sufficient-in fact, is preferable. I therefore wind a few turns of wire around the call-bell magnets, so that the number of watts expended therein ismuch less relatively than that required when the bell is rung from a distant station; I include these turns or coils oflow resistance in series with the calling generator. I prefer to do this by the use of switches that may be operated coextensive with the process of turning the crank for generating the necessarysignaling-current at the same time and by the same agency.

I prefer to remove the high-resistance callbell coils from the circuit at the calling sta-' tion.

In the drawings section A is shown with the parts in the position they assume when a call is being sent from the station by turning the crank a. It will be seen that the short circuit 7 around the generator at is broken at a and that the generator is in series circuit with low-resistance magnet-coils a and a", (the resistance and power of the coils is typified by their relative size,) by wire 4* 5 to main-circuit conductor 2 to B, thence by wire 5 through coils b and Z9 wire 3, brush b through disk on shaft 19, thence through short-circuiting wire '7", wire 6" to hook-wire 8 to terminal B, thence to main circuit conductor 1, thence back to terminal A, wire 8, wire 6, back to the generator. The path through station 0 C is an exact duplicate of that just traced through station E. The calling-circuit will divide, a portion will pass through coils in call-bell of station E, and an approximately-equal portion, less resistance due to intervening line-resistance, will pass through the coils in call-bell of station 0, as they are in parallel circuit.

The high-resistance coils of the call-bell in station A have been removed, as described, and the generator in series with similar coils of low resistance have been substituted.

Vhen the telephone-receivers have been lifted from the hooks precedent to conversation, the circuits are completed only through the talking instruments.

The high resistance of the bell-magnet coils that are left in parallel circuit at the stations which are not engaged in conversation in virtue of the high coefficient of self-induction, due in a great measure to the large number of turns of wire around the core, will repel the high vibrating voice-currents, but will permit the passage of the more slowly vibrating signal-currents.

I do not desire it understood that I wish to limit my invention to the specific construction shown, but that I reserve to myself the right to make such changes in the form and arrangements of the various parts of the apparatus as will fall within the spirit and scope of my invention.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

1. In a telephone system, two main conductors, a plurality of stations connected thereto, each station calling apparatus comprising a call-bell magnet provided with coils of relatively-high resistance normally in circuit, independent call-bell-magnet coils of low resistance normally cut out, one terminal of each pair of coils connected to the same main conductor, the remaining terminal of each pair of coils terminating in contact-points, and a switch connected to the other main conductor, normally in contact with the terminal of the high-resistance coil and adapted to close the circuit from the source of electricity through the low-resistance coils when current is sent to line and to open the circuit of the high resistance coils, substantially as set forth. 7

2. In a system of telephone-circuits, two main conductors,call-bell-magnet coils of relatively-high resistance at each station, normally in circuit between the said main con ductors, said coils being cut out of circuit at the calling station, other call-bell -magnet forth.

3. In a system of inultiple station telephonecircuits, two main conductors, call-bell-magnet coils of relatively-high resistance at each station, normally in a bridging' circuit between said main conductors, call-bell-magnet coils of relatively-low resistance at each staother stations, the arrangement being such that the high-resistance coils are cut out and the low-resistance coils cut in at the calling station, substantially as described.

4. In a system of multiple-station telephonecircuits, two main conductors, call-bell-magnet coils of relatively-high resistance normally in a circuit between the said main conductors, independent call-bell-magnet coils of relatively-low resistance normally out of circuit, an electric generator adapted when operated to open the circuit of the said highre sistance call-bell-magnet coils and to close the circuits of the said low-resistance call-bellmagnet coils, substantially as set forth.

5. In a system of multiple-station telephonecircuits, two main conductors, call-bell-magnet coils of relatively-high resistance, independent call-bell-magnet coils of relativelylow resistance, and an electric generator at each station, the arrangement being such that all the high-resistance call-bell-magnet coils are normally in circuit between the said main conductors,at the calling station the said highresistance coils are removed from the said independent main circuit, and the said low-resistance coils in series with the generator are adapted to be included therein,and when talking the generator and all of said coils at the talking stations are removed from the said main circuit, substantially as set forth.

6. In a system of multiple station telephonecircuits, two main conductors, call-bell-mag net coils of relatively-high resistance at each station normally in a bridging circuit between the main conductors, call-bell-magnet coils of relatively-low resistance at each station normally out of circuit, an electric generator for sending calls at each station, normally short-circuited, adapted when operated to be connected in series with the said lowresistance call-belhmagnet coils,and to open the circuit of the high-resistance call-bellmagnet coils at the calling station, substantially as set forth.

In testimony whereof I have signed this specification, in the presence of two subscribing witnesses, this 30th day of June, 1899.

DANA MONEIL.

Witnesses:

G. T. H. BABCOCK, GEO. L. HARNER. 

